W. Wislicenus and others, of which the following examples
must suffice ; «!
;,ITn ~ QJ Ir,CO.CIL,COOCJir>
Arctic rsirr. -HvmmyUmnxoii: -estcfP -f C0HP)OH.
K'OOCJlr, I CI !....('( K><\,1 1,, .- ILCCU'IUCOOCoIlr,
|M,niii<:<-st.-r. Acvlir CSKT. l'Wmyl:u:«:tic ester. " -| 'C
1 I:,.( '< X )G,I Ir, <>x.'ilylaa>ti<: estc-r. "-|- C,l 1^011.
From this it would appear that condensation might always be.
effected between an ester on the one hand and a compound
containing the group CIL.CO on the other. This seems very
generally to be the rase, and Claisen has succeeded in pro-
ducing condensation products between esters and ketones or
aldehydes containing this group. (See Prep. 100, p. 212.)
The formula for ethyl aeetoacetatc would imply the properties
of a ketone, a view which is borne out.by its reduction to a
and by its behaviour with phenylhydra/.ine and hydroxylamine.
The latter reactions give rise to the formation of the usual
phenylhydraxone and oximc, whilst a molecule of alcohol is also
removed resulting in a closed chain, in the former case phenyl-
methylpynizolone, and in the latter methylisoxazolone being"
I ' II " I
The "mcthylcnc" group (CH2) standing between two CO
groups, such as occurs in acetoacetic ester, is characterised by
certain properties, which are shared by all compounds of similar
structure, vi/., by their behaviour towards nitrous acid, diazo-
benxcne salts, and metallic sodium or sodium alcoholate.
The first reaction leads to the formation of isonitrosoacetone,
cn.,.co.cii,,.cooa,irB + UNO., = CII.,.CO.CTT:NOII + co.,